SATURDAY, April 6 (HealthDay News) -- Black breast cancer patients are more likely to die than white patients, regardless of the type of cancer, according to a new study.

This suggests that the lower survival rate among black patients is not solely because they are more often diagnosed with less treatable types of breast cancer, the researchers said.

For more than six years, the researchers followed nearly 1,700 breast cancer patients who had been treated for luminal A, luminal B, basal-like or HER2-enriched breast cancer subtypes. During that period, about 500 of the patients had died, nearly 300 of them from breast cancer.

Black patients were nearly twice as likely as white patients to have died from breast cancer. The researchers also found that black patients were less likely than white patients to be diagnosed with either the luminal A or luminal B breast cancer subtypes.

"African-Americans were more likely to have the hard-to-treat triple-negative breast cancer subtype and had a lower likelihood of having the luminal A subtype, which tends to be the most treatable subtype of breast cancer and has the best prognosis," study author Candyce Kroenke, a research scientist at Kaiser Permanente, said in an association news release.

Kroenke and her colleagues found, however, that lower survival among black patients was consistent across breast cancer subtypes. Black patients were 2.3 times more likely to die from the luminal A breast cancer subtype compared with white patients, 2.6 times more likely to die from the luminal B subtype, 1.3 times more likely to die from the basal-like subtype and 2.4 times more likely to die from the HER2-enriched subtype.

The study is scheduled for presentation at the annual meeting of the American Association for Cancer Research, which is taking place April 6 to 10 in Washington, D.C. Data and conclusions presented at meetings typically are considered preliminary until published in a peer-reviewed medical journal.